Watertight pusher

ABSTRACT

A watertight pusher device for watches or the like employs a tube having means for connection to the case of a watch, a spring mounted pusher head secured to the tube for sliding movement axially on the tube, and a screw member in threaded connection with the pusher head. The screw member has an inner head which extends out of the tube, the inner head having a diameter or dimension to provide a shoulder for engagement with the adjoining end of the tube. The pusher device is made to be useful for a range of watch cases having different wall thicknesses by providing the inner head with a non-circular outer surface adapted for mating engagement with a tool to rotate the screw member. The inner head has a length sufficient to allow it to be shortened without the loss of a sufficient area of purchase to enable rotation of the screw member. Also, the pusher head of the device is provided with a non-circular outer surface adapted for mating engagement with a tool so that the pusher head and the tube to which it is connected may be rotated.

Unite States Patent [191 Zellweger 1 WATERTlGI-IT PUSHER [75] Inventor:Conrad Zellweger,Chene-Bougeries,

Switzerland [73] Assignee: Waldman Corporation, Parsippany,

22 Filed: May 5,1972

[21] Appl. No.: 250,789

Primary ExaminerGeorge H. Miller, Jr. Attorney-Harry G. Shapiro [57]ABSTRACT A watertight pusher device for watches or the like employs atube having means for connection to the case of a watch, a springmounted pusher head secured to the tube for sliding movement axially onthe tube, and a screw member in threaded connection with the pusherhead. The screw member has an inner head which extends out of the tube,the inner head having a diameter or dimension to provide a shoulder forengagement with: the adjoining end of the tube. The pusher device ismade to be useful for a range of watch cases having different wallthicknesses by providing the inner head with a non-circular outersurface adapted for mating engagement with a tool to rotate the screwmember. The inner head has a length sufficient to allow it to beshortened without the loss of a sufficient area of purchase to enablerotation of the screw member. Also, the pusher head of the device isprovided with a non-circular outer surface adapted for mating engagementwith a tool so that the pusher head and the tube to which it isconnected may be rotated.

12 Claims, 4 Drawing Figures PATENIEUSEPI H 3, 757. 5 1 2 FIG. 3 FIG. 4

1 WATERTIGHT PUSHER The invention relates to improvements in watertightpushers for watches or the like.

BACKGROUND OF THE INVENTION is locked a screw which extendslongitudinally in the tube and out through an opening provided at theinner end of the tube. The screw is made with a slotted head, the headpresenting a shoulder to engage the end of the tube adjacent the openingto limit the outward displacement of the pusher head. A compressionspring is housed within the tube around the shank of the screw toresiliently urge the pusher head outwardly of the device.

Watch cases vary in wall thickness. To take care of the differentthicknesses of the cases in which the pusher is threaded or secured, ithas been the practice for pusher manufacturers to stock an assortment ofscrews with different head lengths. Given the tolerances necessary forthe effective functioning of a chronograph, these pushers are very oftenfinished after having been mounted in placeand the length of the head isreduced or decreased. As a result, the slot in the head of the screw isshortened to such an extent that disassembly becomes difficult if notimpossible.

It has been proposed to overcome these difficulties by providing thepusher shaft with a retaining ring which is inserted into a groove andby lengthening the shaft by means of a partly tubular flange which maybe adjusted to the length desired. Such an arrangement, however,complicates the assembly of the device and increases its cost.

It has been the practice to assemble watertight pushers on watch casesin separate parts. Traditionally, the pusher head of the device has beenmade of a circular contour. As a result, the pusher device may not bescrewed onto the case in the assembled state of the device.

SUMMARY OF THE INVENTION The primary object of the invention is toovercome the aforementioned limitations and disadvantages of the priorart watertight pusher devices.

In accordance with the invention, the screw member of the assembly ismade with an inner head which has a non-circular outer surface which isadapted for mating engagement with a tool for rotating the screw member.By eliminating the slot in the head, thelength of the head may beshortened or adjusted so that a screw member of only one size is usefulfor a substantial range of watch cases having different wallthicknesses. The

head of the screw can be cut to length at any time desired, and suchoperation can be accomplished on the assembled pusher. Also, theadjustment of the length of the head of the screw member does notinvolve any difficulty if it. is necessary to disassemble the device.

The pusher head or push button element of the device also is providedwith a non-circular outer surface so that such surface may be engaged bya mating tool to enable rotating the pusher head and the tube to whichit is connected. As a result, the pusher device may be locked to thecenter case of a watch in the assembled state of the device. Moreover,by making the non-circular outer surface of convex portions, anesthetically pleasing appearance is furnished in addition to thefunctional purpose which is served. Also, such contour of the pusherhead easily distinguishes this part from the crown on the watch which isnormally serrated or knurled.

These, and other advantages and improved results of the invention willbe apparent from the following description of a preferred embodiment ofthe invention, taken in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross section of a pushermade in accordance with the invention, the device being shown connectedto the center case of a watch; and

FIGS. 2-4 show several contours of the pusher head element of thedevice.

DESCRIPTION OF THE PREFERRED EMBODIMENT The pusher illustrated comprisesa tube 1 having an externally threaded portion at one end to enable itto be threaded into a matingly threaded portion of a center case 2 of awatch. A pusher head 3 is mounted for sliding movement axially on thetube 1, and the pusher head is secured to the tube so that they may berotated together. For this purpose, the parts are provided with matinggrooves or splines 4 and 5.

The watertightness of the device is achieved by means of a sealingelement or ring 6 held in an annular groove 7 formed at the upper end ofthe tube 1. The sealing element is held in the groove by a retainer ring8. As shown, the sealing eement bears against the interior core orbarrel 9 of the pusher head or push button 3.

The tube 1 presents an internal flange 10 with an opening 11 to permitthe passage of the shank of a screw member 12. The screw member isthreaded into the threaded bore 13 of the barrel 9 of the pusher head.The screw member 12 has an inner head 14 which provides a shoulder forengagement with the adjoining end of the tube. y

A compression spring 15 is positioned in the tube 1 and surrounds theshank of the screw member 12. One end of the spring bears against theinternal flange 10 of the tube, and the other end bears against the endof the barrel 9 of the pusher head. As a result, the pusher head isurged outwardly, the outer displacement being limited by the engagementof the head 14 with the flange 10 of the tube.

The inner head 14 has a non-circular cross section and provides anon-circular outer surface adapted for mating engagement with a tool forrotating the screw member 12. Preferably, the head 14 has a hexagonalcross section. It will be evident that if the length of the head isaltered or shortened, such alteration does not change the outer profileof the head. Thus, the manufacturer of the pusher device of theinvention need stock only devices having screw members in which theheads are of desired maximum length to accommodate the most thick wallthickness of a range of watch cases with which the devices will beassembled. The screw member may have a predetermined length before beingmounted onto a watch, taking into account the particuinconvenience orproblem in subsequent disassembly. Thus, the pusher manufacturer maysubstantially reduce the stocking of parts. In addition, repair of thedevice is greatly simplified. If a pusher has to be replaced, the watchmaker may buy a pusher and adjust it to the correct length by cutting orshortening the inner head of the screw member of the pusher. Forexample, the inner head of the screw member may be made with a length ofapproximately 4 mm.

Although it is preferred that the inner head 14 of the screw member havea hexagonal cross section, it is within the scope of the invention tomake the contour square, elliptical, or oval. Also, instead of the tube1 being formed with a threaded portion to enable it to be screwed intothe case 2, such end of the tube may be formed to enable the tube to beforce-fitted to the case.

As shown in FIGS. 2, 3 and 4, the pusher head 3 has a non-circular crosssection to provide a non-circular outer surface or profile. As shown inFIG. 2, three convex portions a, b and having a radius of curvature R,are connected to one another by three convex portions d, e and f havinga larger radius of curvature R In the form of the invention illustratedin FIG. 3, the cross section of the pusher head 3 comprises four convexportions each having a radius of curvature R the portions beingconnected to one another or coming together to form in the nature of acurvilinear square.

In the form of the invention illustrated in FIG. 4, the contour of thepusher head or push button presents two convex portions with differentradii of curvature R, and R which furnish an elliptical shape.

In the three forms of pusher head illustrated, a tangent at the pointsof intersection of the convex lines does not intersect any of the lines.

It is also within the scope of the invention to shape the pusher head 3by providing several convex portions wherein the radii of curvature varyprogressively, the convex portions being connected to one another in acontinuous fashion.

The non-circular outer surface or profile of the pusher head 3 isadapted for mating engagement with a female tool so that the pusherhead, and consequently the tube 1 to which it is splined, may be rotatedto effeet the connection and disassembly of the device from the centercase 2 of a watch.

It is believed that the advantages and improved results of the inventionwill be apparent from the foregoing detailed description of a preferredembodiment of the invention. Various changes may be made withoutdeparting from the spirit and scope of the invention as sought to bedefined in the following claims.

I claim: a

I. In a watertight pusher device for watches or the like comprising atube having means for connection to the case of a watch, a pusher headsecured to the tube for sliding movement axially on and for rotationwith the tube, the pusher head having a threaded bore, a screw memberthreaded into the bore extending longitudinally in the tube, the screwmember having an inner head extending out of the tube, the inner headprovidwhich vary progressively.

ing a shoulder for engagement with the adjoining end of the tube, and acom-pression spring in the tube surrounding the screw member to normallyurge the pusher head outwardly of the tube, the improvement wherein theinner head has a non-circular cross section providing a non-circularouter surface adapted for mating engagement with a tool for rotating thescrew member, said outer surface allowing the inner head to be shortenedand still allow engagement by a tool to thereby enable the device to beused for a range of watch cases having different wall thicknesses.

2. In a watertight pusher according to claim 1 wherein the non-circularouter surface is hexagonal.

3. In a watertight pusher device according to claim I wherein the pusherhead has a non-circular cross section providing a curvilinear outersurface adapted for mating engagement with a tool to rotate the pusherhead and the tube therewith.

4. In a watertight pusher device according to claim 3 wherein thenon-circular outer surface of the pusher head is formed of convexportions.

5. In a watertight pusher device according to claim 4 wherein the convexportions have a variable curvature.

6. In a watertight pusher according to claim 4 wherein the convexportions comprise three portions with a small radius of curvatureconnected by three portions having a larger radius of curvature.

7. In a watertight pusher device according to claim 4 wherein the convexportions have radii of curvature which vary progressively.

8. In a watertight pusher device for watches or the like comprising atube having means for connection to the case of a watch, a pusher headsecured to the tube for sliding movement axially on and for rotationwith the tube, the pusher head having a threaded bore, a screw memberthreaded into the bore extending longitudinally in the tube, the screwmember having an inner head extending out of the tube, the inner headproviding a shoulder for engagement with the adjoining end of the tube,and a com-pression spring in the tube surrounding the screw member tonormally urge the pusher head outwardly of the tube, the improvementwherein the pusher head has a non-circular cross section providing acurvilinear outer surface adapted for mating engagement with a tool forrotating the pusher head and the tube.

9. In a watertight pusher device according to claim 8 wherein thecurvilinear outer surface of the pusher head is formed of convexportions.

10. In a watertight pusher device according to claim 9 wherein theconvex portions have a variable curvature.

11. In a. watertight pusher device according to claim 9 whereintheconvex portions comprise three portions with a small radius ofcurvature connected by three portions having a larger radius ofcurvature.

12. In a watertight pusher device according to claim 9 wherein theconvex portions have radii of curvature

1. In a watertight pusher device for watches or the like comprising atube having means for connection to the case of a watch, a pusher headsecured to the tube for sliding movement axially on and for rotationwith the tube, the pusher head having a threaded bore, a screw memberthreaded into the bore extending longitudinally in the tube, the screwmember having an inner head extending out of the tube, the inner headproviding a shoulder for engagement with the adjoining end of the tube,and a compression spring in the tube surrounding the screw member tonormally urge the pusher head outwardly of the tube, the improvementwherein the inner head has a non-circular cross section providing anon-circular outer surface adapted for mating engagement with a tool forrotating the screw member, said outer surface allowing the inner head tobe shortened and still allow engagement by a tool to thereby enable thedevice to be used for a range of watch cases having different wallthicknesses.
 2. In a watertight pusher according to claim 1 wherein thenon-circular outer surface is hexagonal.
 3. In a watertight pusherdevice according to claim 1 wherein the pusher head has a non-circularcross section providing a curvilinear outer surface adapted for matingengagement with a tool to rotate the pusher head and the tube therewith.4. In a watertight pusher device according to claim 3 wherein thenon-circular Outer surface of the pusher head is formed of convexportions.
 5. In a watertight pusher device according to claim 4 whereinthe convex portions have a variable curvature.
 6. In a watertight pusheraccording to claim 4 wherein the convex portions comprise three portionswith a small radius of curvature connected by three portions having alarger radius of curvature.
 7. In a watertight pusher device accordingto claim 4 wherein the convex portions have radii of curvature whichvary progressively.
 8. In a watertight pusher device for watches or thelike comprising a tube having means for connection to the case of awatch, a pusher head secured to the tube for sliding movement axially onand for rotation with the tube, the pusher head having a threaded bore,a screw member threaded into the bore extending longitudinally in thetube, the screw member having an inner head extending out of the tube,the inner head providing a shoulder for engagement with the adjoiningend of the tube, and a com-pression spring in the tube surrounding thescrew member to normally urge the pusher head outwardly of the tube, theimprovement wherein the pusher head has a non-circular cross sectionproviding a curvilinear outer surface adapted for mating engagement witha tool for rotating the pusher head and the tube.
 9. In a watertightpusher device according to claim 8 wherein the curvilinear outer surfaceof the pusher head is formed of convex portions.
 10. In a watertightpusher device according to claim 9 wherein the convex portions have avariable curvature.
 11. In a watertight pusher device according to claim9 wherein the convex portions comprise three portions with a smallradius of curvature connected by three portions having a larger radiusof curvature.
 12. In a watertight pusher device according to claim 9wherein the convex portions have radii of curvature which varyprogressively.